Carburetor



Dec. 2, 1.947. L.. E. OLIVER ET AL CARBURETOR Filed Nov. 21, 1944 2 sheets-sheet 1 I'NVENTORS leo E. Olwe'r Ray Carson Sn www@ ATTORNEYS Dec; 2, 1947. l.. E. OLIVER ET AL CARBURETOR Filed Nov. 21, 1944 2 sheets-sheet z C Im @hun n Er A F, j,

' ATTORNEYS Patented Dec. 2, 1947 UNITED STATES PATENT OFFICE CARBURETOR Leo E. Oliver, Sanger, and Ray Carson, Sr., Vallejo, Calif.

Application November 21, 1944, Serial No. 564,450

(Cl. IS- 180) 16 Claims. l

This invention is directed to, and it is an object to provide, a carburetor especially designed for use in a motor vehicle fuel system which includes a fuel res-ervoir containing a gaseous fuel, such as natural gas, under high pressure, a conduit lead-ing from the reservoir to the carburetor, and a pressure regulator interposed in the conduit; such a fuel system being advantageous for automobiles, trucks, motor boats, and aircraft.

Another object of the invention is to provide a gaseous fuel carburetor which is constr-ucted so as to effectively and economically meter the fuel, in correct proportions, at both low and high engine speeds; the carburetor including an effective idling feed to maintain the engine in operation when the throttle is closed.

An additional object of this invention is to provide a carburetor which requires no air choke mechanism for ease of starting.

A further object is to provide a carburetor for gaseous fuel, arranged so that exterior gas leaks cannot occur, as all Working parts of the car- 'buretor are subject to vacuum from the engine.

It is also an object to incorporate, in the carburetor, a low speed valve, and a high speed valve in unique combination; such valves being actuated in progressive order by a novel cam arrangement operated from the butterfly valve supporting throttle shaft of the device.

These objects are accomplished by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawings similar characters of reference indicate corresponding parts in the several views:

Figure 1 is a sectional elevation of the improved carburetor, with the low and high speed valves closed.

Figure 2 is a similar view, on reduced scale, but showing the low speed valve open.

Figure 3 is similar to Fig. 2, but shows both the low and high speed valves open.

Figure 4 is a diagrammatic view of the system in which the carburetor is embodied.

Referring now more particularly to the characters of reference on the drawings, the carburetor comprises a tubular body I open at one end to atmosphere and provided at the other end with an attachment ange 2 adapted to connect with the corresponding flange 3 of an engine manifold 4, A throttle shaft 5 extends diametrally through the body I intermediate its ends, and within said body the throttle shaft carries an air flow control butterily valve 6, mounted as hereinafter described in detail, and which butterfly valve is 2 diagonally disposed when closed as shown in Fig. 1. The shaft 5 is fitted outside body I with a lever 'I te which a control rod 8 connects, said rod cxtending from the throttle pedal in the operators compartment.

The body I forms the mixing chamber 9 oi the carburetor, and a tubular, cylindrical housing I projects laterally from body I intermediate its ends; such housing being initially open at its outer end, and communicating at its inner end with chamber 9 directly above the low side of the butterfly valve 6 when the latter is closed.

A tubular sleeve II closely and symmetrically engages in housing I0, and adjacent its outer end this sleeve is threaded into the housing as at I2 for axial adjustment. The sleeve II is normally but releasably held in locked position by a nut I3 threaded thereon and abutting the adjacent end of housing IIJ.

The sleeve II carries the low and high speed valve assembly, which comprises the following:

A tubular plunger I4 is slidably disposed ln sleeve II with its` inner end intermediate the sleeve ends; said inner end of the plunger being formed as an annular, radially projecting flange I5 riding in the sleeve. A closure plug I6 is threaded as at Il into the housing at its outer end, and a helical compression spring I8 engages between said plug and the flange I5 normally urging plunger` I4 toward body I. In the advanced position of the plunger, an annular, taper valve I 9 thereon engages a cooperating seat 2B- formed in the inner end of sleeve II. This is the high speed valve of the carburetor, and adjacent but short of said valve I9 there is space between the sleeve II and plunger I4 forming a gas ilow chamber 2l which communicates with the interior of plunger I4 by means of a circumferential row of ports 2 Ia in the latter. The inner end portion of plunger I4 projects beyond sleeve II to a termination in radial alinement adjacent but clear of the throttle shaft 5.

A mushroom head metering valve 22 cooperates with an annular taper valve seat 23 formed in plunger I4 at the outer end thereof, and said valve 22 includes an actuating stern 24 which extends through said plunger in clearance relation except at the inner end thereof where a close running iit is provided; such clearance providing a gas flow channel 25. A row 0f circumferentially spaced ports 26 open through the plunger I4 into channel 25 beyond the sleeve II. The ports 2Ia likewise are in communication with channel 25. It should be noted that ports 2Ia are of greater diameter than ports 26.

A compression spring C seats between the head of valve 22 and the plug I6 normally holding said valve 22 closed; valve 22 being the slow speed valve of the carburetor.

The valve stem 24 terminates beyond the inner end of plunger I4 and is fitted with an enlarged head 2T. A flat segmental cam 28 is xed on throttle shaft 5 radially thereof, with the working edge of said cam eccentric to the shaft and riding the head 21 on valve stem 24; said cam extending across the shaft 5 on the side opposite the butter'- ily valve 6, and being disposed so that the low end of the cam engages head 21 when the buttery valve is closed.

The butterfly valve is rotatably supported Aon the shaft 5 by a hanger H, and all motion of said butterfly valve is imparted thereto by the cam. However at opposite ends of the back edge thereof the cam initially has some clearance from the butterfly valve. When the throttle shaft 5 is in carburetor closing position, one end of the back edge of cam 28 engages an upstanding compression spring S on butterfly valve 6 and urges the latter to closed position. (See Fig. l.) From this position the throttle valve can rotate to some extent in a clockwise direction without the other end of the back edge of the cam engaging the butterfly valve on the opposite side of the shaft 5. The advantage of thisindependent movement of the cam relative to the. butterfly valve will hereinafter appear.

Gaseous fuel is supplied to the carburetor by a conduit 29 which leads from a tank 30 where the fuel, preferably natural gas, is held under pressure; there being a manually adjustable pressure regulator 3| interposed in conduit 29 and disposed in the operators compartment. The conduit 29 is connected to the carburetor by a fitting 32 on and opening through the plug I6.

Fuel, under regulated pressure, feeds from conduit 29into therchamber 33 formed in sleeve II between Valve 22 and plug IB. When the throttle shaft 5 and the cam 28 are initially rotated in a clockwise direction from the closed position of Fig. l, the cam moves independently ofthe but-- terfly valve andrbeginsto depress head 21 and stem 24 causing an initial opening of valve 22. Gasous fuel thenv first feeds into channel 25 and out of ports 25 into the mixing chamber 9. As

this occurs before the butterfly valve 6 opens, the

effect of an air choke is automatically obtained.

"With, continued clockwise rotation of the throttle shaft and cam, thevalve 22 is fully opened, as shown in Fig. 2, with maximum low speed fuel delivery. throughports 26.

Thereafter, with furtherclockwise rotation of said shaft and cam, the head 21 abutsagainst the adjacent end of plunger I4 and. causes openingv of high speed valve I9; fuel then passing from channel 25 through` ports 2Ia into chamber 2I and thence about valve vI9 into mixing chamber 9.

With opening of valves22 and I9, as above described, except at the initial opening of valve 22, the cam engages and there is an accompanying progressive opening ofgbuttery valve 6 to provide access of air in proportion to fuel increase; fuel delivery being properly regulated to butterfly valve position `by axial adjustment of sleeve II which carries the Valve assembly.

The springs I8 and C return the valves to closed position in inverse progressiveV order to that 'above described, when the throttle shaft 5 is rotated counter-clockwise.

Idling fuel mixture is delivered to chamber 9,

when valves I9 and 22 are closed, by the following arrangement:

An air feed duct 34 leads through body I parallel to its axis and connects between atmosphere and the mixing chamber 9; there being a needle valve 35 t0 control air ow through said duct. Another cylindrical housing 36 projects from body I below housing I, and is closed at its outer end while its inner end is in communication with a passage 3l leading to duct 34 inwardly of needle valve 35.

Fjuel is fed inte the housing 36 by a lateral conduit 38 leading from fitting 32 through the closed outer end of said housing. Fuel under pressure in housing 36 is fed into passage 31 and duct 34 in controlled quantity through the medium of a vacuum actuated, spring returned valve unit 39. The valve unit 39 includes an adjustment nut 45 which can be set t0 insure closing of the Valve against fuel pressure tending to open the same, when the vacuum falls below idling pressure.

From the foregoing description it will be readily seen Vthat there has been produced such a device as substantially fulfills the objects of the invention as set forth herein.

Whilev this specification sets forth in detail thepresentand preferred construction of the device, still in practice such deviations from such detail may be resorted toas do not form a departure from the spirit of the invention, as de- 1in-ed by the appended claims.

v Having thus described the invention, the following is Claimed as new and useful andupon which Letters Patent is desiredi l. AY carburetor-comprising a body forming a mixing chamber open at one end to atmosphere and adapted to feed a fuel mixture from the other end, a, butterfly valve mounted for movemen-t in said chamber intermediate the ends thereof, a fuel meteringv and delivery valve assembly mounted in. connection with the body and in communicationwith the chamber between saidother endthereof and the butterfly valve, the butteryvalve being supported by athrottle shaft, and a cam mounted on rr the -throttleshaft operative-toengage andprogressively open said valve assembly upon rotation Aofsaid shaft to open the butterfly valve.

2. A; carburetor comprising a body forming a mixing chamber open at one end to atmosphere and adapted to feed a fuel mixture from the other end, av butterfly valve mounted Vfor movement in said chamber intermediate the ends thereof, a fuel 'metering anddelivery valve assembly mounted in connection withV the body and in communication with the chamber between said other end thereof and thebutterfly valve, the butterfly valve being supported by al4 throttle shaft, and a cam mounted on the throttle shaft operative to engage and progressivelyv open said valve assembly upon rotation of said shaft to open` the butterfly valve; said` valve assembly being spring 'urged toward closed position.y

3. A carburetor comprising abody forming a mixing chamber open at one end to atmosphere and adaptedr to feed a fuel mixture from the other end, a-butterfly valve mounted for movement in said chamber intermediate the ends thereof, a ,fuel metering and delivery valve assembly mounted in connection with the body and incommunication with thechamber between said other end thereof and` the butterfly valve, and meansA operative to first open said valve assembly slightly and to a predetermined extent independently of the butteriiy valve, and to then open said valve assembly and butterfly valve together and progressively.

4. A carburetor comprising a body forming a mixing chamber open at one end to atmosphere andadapted to feed a fuel mixture from the other end, a butterfly valve mounted for movement in said chamber intermediate the ends thereof, a fuel metering and delivery valve assembly mounted in connection with the body and in communication with the chamber between said other end thereof and the butterfly valve, and means operative to rst open said valve assembly slightly and to a predetermined extent independently of the butterfly valve, and to then open said valve assembly and butterfly valve together and progressively; the butterfly valve being rotatably mounted on a throttle shaft extending into the mixing chamber, and said means including a cam fixed on said shaft, said cam upon rotation of the shaft in one direction lbeing arranged to rst engage and partially open the valve assembly and to then engage and open both the valve assembly and butterfly valve.

5. A carburetor comprising a body forming a mixing chamber open at one end to atmosphere and adapted to feed a fuel mixture from the other end, a butterfly valve mounted for movement in said chamber intermediate the ends thereof, a fuel metering and delivery valve assembly mounted in connection with the body and in communication with the chamber between said other end thereof and the butterfly valve, said valve assembly including a low speed valve and a high speed valve, and means to open the butterfly valve and said valve assembly together and progressively; the low speed valve opening nrst followed by the opening of the high speed valve.

6. A carburetor as in claim 5 in which said valve assembly includes a stem depressible to open the low speed valve, and a plunger depressible to open the high speed valve; said means being operative to depress the stem, and the stem after predetermined depression thereof, engaging and depressing the plunger.

7. A carburetor comprising a body forming a mixture chamber open at one end to atrnsophere and adapted to feed a fuel mixture from the other end, a butterfly valve mounted for movement in said chamber intermediate the ends thereof, a cylindrical housing projecting laterally from the body, the housing being closed at its outer end and in communication at its inner end with the mixing chamber between said other end thereof and the butterfly valve, a fuel feed conduit connected into the housing adjacent its outer end, a fuel metering and delivery valve assembly slidab-ly mounted in the housing and closing toward the mixing chamber, spring means normally urging the valve assembly to closed position, and means to open the butteriiy valve and said valve assembly together and progressively.

8. A carburetor comprising a body forming a mixing chamber open at one end to atmosphere and adapted to feed a fuel mixture from the other end, a butterfly valve mounted for movement in said chamber intermediate the ends thereof, a cylindrical housing projecting laterally from the body, the housing being closed at its outer end and in communication at its inner end with the mixing chamber between said other end thereof and the butterfly valve, a fuel feed conduit connested into the housing adjacent its outer end, a tubular plunger slidable in the housing, an annular valve between the housing and plunger closed upon movement of the plunger toward the mixing chamber, spring means normally urging the plunger to valve closing position, said plunger having ports therethrough on opposite sides of said annular valve, another valve arranged to close the end of the plunger opposite the mixing chamber, said other valve including a valve stem extending through the plunger and terminating beyond the inner end of the latter, there being a fuel flow clearance in the plunger from saidother valve to said ports, other spring means normally urging said other valve to closed position, and means operative to first engage and move said stem to open said other valve, and to then engage and move the plunger to open said annular valve.

9. A carburetor as in claim 8 in which said spring means cooperating with the plunger, and other spring means cooperating with said other valve, comprise compression springs, one within the other, engaged between the closed outer end of Ythe housing and adjacent portions of the plunger and Iother valve.

i0. A carburetor comprising a body forming a mixing chamber open at one end to atmosphere and adapted to feed a fuel mixture from the other end, a butterfly valve mounted for movement in said chamber intermediate the ends thereof, a cylindrical housing projecting laterally from the body, the housing being closed at its outer end and in communication at its inner end with the mixing chamber between said other end thereof and the butterfly valve, a fuel feed conduit connected into the housing adjacent its outer end, a tubular plunger slidable in the housing, an annular valve between the housing and plunger closed upon movement of the plunger toward the mixing chamber, spring means normally urging the plunger to valve closing position, the butterfly valve being mounted on a transverse throttle shaft in the body, and a cam mounted on said shaft, said cam being arranged to function upon rotation of the shaft to first cause movement of the stem and opening of said other valve, and then cause movement of the plunger and opening of said annular valve.

l1. A carburetor as in claim 10 in which both the plunger and stem project into the mixing chamber to adjacent but short of the throttle shaft, the stem projecting slightly further than the plunger, and a head on the stem beyond the plunger; the cam riding said head, and the head engaging the plunger after predetermined movement thereof by the cam.

12. A carburetor as in claim 10 in which the butterfly valve is rotatable on the throttle shaft; said cam being operative to first cause movement of the stem and partial opening of said other valve independent of the butterfly valve, and to then engage the butterfly valve and thereafter cause opening thereof progressively with continued opening of` said other valve and subsequent opening of said annular valve.

13. A carburetor comprising a body forming a mixing chamber open at one end to atmosphere and adapted to feed a fuel mixture from the other end, a butterfly valve normally closing the passageway through the body, a normally closed gas valve connected with the body between said other end thereof and the butterfly valve, such gas valve including a valve stem projecting into the body, a cam mounted for rotation within the body, such cam being engageable with said stem to operate said gas valve and said cam being also engageable with the butterfly valve to move it mee-nete 7 from closed to "open position; andfxeailsu t'ffd fuel to the gas" valve;l

14; A carburetor asin'blain 13=in=wleh the movement of thefcam first engages and'imves the stem to partially open tliegasvalve, and thereafter the cam engages and opens the butter'e fly Valve While continuing to move the stem' te further open the ga'svalvei 15. A carburetor so'nilbrisiitg abody forming' a mixture chamber openat one end to atmosphere andv adapted to disc'zhargev afuelmixture from the other end to an engine, a-butterflyvalv'e 'normallyv closing the-passage throghthefbody, a source of fuel supply, two fuel feed-passages lead'- ing from the fuelvsupplysource to saidlother'end of the chamber and to the same sidefof-'thevbuttei'e fly valve, a valve in each passagei one passage constituting a fuel feed for the engine when idling, and the other constituting a main fuel feed to the engine, and means operable to partially open the valve in the main fuel feed passage Without opening the butterfly valve 'whereby fuel may flow from thev main fuel supply to the-engine Without atmospheric'air being mixed therewith.

16,.A=1 carburetor'. as in claim" 15; including means' toi` progressively move the last* named valve from said partially opened position to full openposition synchronously with the opening of 5- the: butterfly valve` LEO E. OLIVER. RAY CARSON, SR'.

REFERENCES' CITEDr Thefollow'ing references are of record in the file of this'patent:

UNITED STATES PATENTS Number Name Date '15 2,027,492' Snodgrass Jan. 14, 1936 2,324,392 Hincl'i'm'an' July 13, 1943 319,971 Bodin@ May 25,- 1943 2,106,903 Tonkin Feb. 1, 1938 2,073,298 Ensign Mar. 9, 193'? 20 2,004,403 Davisson et ai. June 11, 1935 FGREGN PATENTSl Number Country Date 

